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I'm starting to reassemble my LT1 for the 95 Corvette and the piston/rod assemblies do not seem to make sense the way they are numbered. The pistons have arrows which the service manual says should point to the front (as usual). The rods have a chamfer that goes toward the fillet on the crank and the other side of the rod obviously has been rotating against the adjacent rod. When the pistons are arranged according to the numbered order and turned according to how the rods should be oriented, some of the arrows on the pistons do not point forward. Has anyone ever run into this? Do you think the machine shop misnumbered the pistons or did the factory put the pistons on the rods backwards? The pistons have not been removed from the rods, as they were only cleaned, checked, and numbered at the machine shop.
I remember pulling apart an engine years ago with some pistons in backwards and it had a lot of trouble free miles on it. Is the mark related to the piston construction or is it there to make assembly more idiot proof?
From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
I'm thinking when I rebuilt my '95 that the stock pistons, which I didn't reuse, had four valve reliefs so Mr. Goodwrench couldn't get them in backwards. So you should be able to orient the rods per the manual and not worry about the pistons.
From: Good health is merely the slowest possible rate at which one can die
St. Jude Donor '04-'05-'06-'07
Originally Posted by Mr Dave
Do you think the machine shop misnumbered the pistons or did the factory put the pistons on the rods backwards? The pistons have not been removed from the rods, as they were only cleaned, checked, and numbered at the machine shop.
So you're saying then the rods weren't marked from the factory? I really don't remember if mine were or not but if not, I have a stamp set and would have marked them before removal. I see what you're asking now. I wish I had a stock one lying around to look at but I sent them to someone in one of those freebie threads. All I can suggest at this point is trying to arrange them different ways on the bench with the rods oriented correctly and see if you can get all the arrows pointing forward. It doesn't matter which hole a rod came out of anyway, or piston for that matter, assuming all rings and pistons will be new which I'm sure is the case. You are lining these up 1357 on the left and 2468 on the right, right?
It doesn't matter which hole a rod came out of anyway, or piston for that matter, assuming all rings and pistons will be new which I'm sure is the case.
The rings could be new, but not the pistons, if "or did the factory put the pistons on the rods backwards? The pistons have not been removed from the rods". Did whomever numbered the pistons use the same convention for numbering the cylinders, that you are? It doesn't sound like it.
Here's what your problem is ........ You put the backwards pistons on the wrong bank! If you notice you'll have the same number of backwards pistons on the even and odd sides. Someone must have misnumbered the pistons, that's the only explination.